Use of turbulence suppressing agents in water jet looms



United States Patent "ice 3,476,155 USE OF TURBULENCE SUPPRESSING AGENTS IN WATER JET LOOMS Robert O. Carothers, Coraopolis, Pa., assignor to Calgon Corporation, Pittsburgh, Pa. No Drawing. Filed Aug. 26, 1968, Ser. No. 755,402 Int. Cl. D03d 47/32; B6511 25/06 US. Cl. 139-127 6 Claims ABSTRACT OF THE DISCLOSURE The speed, accuracy and efficiency of water jet looms are enhanced by the use of polymeric turbulence suppressing agents in the water added prior to its passage through the jet.

BACKGROUND OF THE INVENTION This invention relates to the process of feeding weft yarns or threads into a warp shed by means of a water jet. The process is applicable to water jet looms such as are discussed in US. Patents 2,998,029 and 3,370,618. Similar looms to which this invention is applicable are discussed in US. Patents 3,180,368; 3,372,711; and 3,233,634. The water jet loom utilizes a stream of water emerging from a nozzle at high velocity to direct the weft. No shuttle is necessary in such a loom.

It is known that the tendency of water to flow turbulently in a pipe can consume much of its energy. Various additives have been proposed to reduce the turbulence in the flow of aqueous systems. See, for example, Dever, Harbour and Seifert US. Patent 3,023,760; Smith US. Patent 3,099,993; Root US. Patent 3,254,719; Smith, Seichter and Adler US. Patent 3,102,548; and Giles and Stern US. Patent 3,290,883. Also of interest is Studies of the Reduction of Pipe Friction with the Non-Newtonian Additive CMC by Riphen and Pelch, a Department of Commerce publication dated April 1963. Carboxymethyl cellulose, sodium polystyrene sulfonate, polyacrylamide and hydrolyzed polyacrylamide are among the water-soluble polymers suggested for turbulence suppression or friction reduction in pipes. Hydrolyzed polyacrylamide derivatives have found wide use as friction reducers in formation fracturing in the petroleum industry. Polyethylene oxide, guar gum, and other high molecular weight water soluble polymers have significantly reduced turbulent flow, or friction loss, in pipes. The polymers referred to in this paragraph are sometimes known as viscoelastic polymers.

It has been observed that polyethylene oxide added to a pipeline irrigation system will increase the area of coverage significantly because the loss of energy in the pipes is correspondingly reduced. See 73 Chem. Eng, No. 16, p. 36 (Aug. 1, 1966). When added to water to be used in a fire hose, polyethylene oxide has been reported to achieve a significantly greater distance of projection of the water.

SUMMARY OF THE INVENTION The water jet loom overcomes many of the difficulties of the conventional mechanical shuttle used to carry a weft back and forth in a loom. The water jet devices are easily controlled, have few moving parts and therefore fewer mechanical breakdowns, and can be made to operate significantly faster than mechanical weft control devices. However, there is a point of speed or efficiency beyond which the water jet loom has not been able to progress, due to the tendency of the jet stream to separate. Accuracy and adjustment of the jet have been difficult to maintain. See Nydam US. Patent 3,381,721.

My invention provides that the addition to the water of a water-soluble polymer as herein defined will signifi- Patented Nov. 4, 1969 cantly improve the coherence of the jet stream throughout its flight, permitting truer accuracy and greater weft velocity. Water jets may be used on wider looms. The effect is not alone one of coherence, adhesion, or viscosity but of friction reduction also, i.e. minimizing turbulent fiow and increasing the incidence of laminar flow, both in the nozzle and during passage through the warp shed. The tendency of the jet stream to separate or form a spray is minimized.

It should be emphasized at this point that in water jet nozzles such as that disclosed by Zahradnik in US. Patent 2,998,029, the weft is fed through the nozzle with the water so that it emerges from the nozzle substantially surrounded or immersed in the jet stream. It may be speculated that the effect of the weft on the turbulent flow of the water as it emerges from the nozzle is significant. My invention smoothes out the flow and provides a steady, solid stream across the warp shed.

On the other hand, my invention is also applicable to jet weft projecting devices of the type discussed by Kobayashi in US. Patent 3,180,368, wherein the weft yarn is contacted with the jet stream after its passage through the nozzle.

The polymers which I may utilize are water-soluble polymers generally having molecular weights of at least 10,000. There is no upper limit, so far as I am aware, to the operable molecular weight, so long as the polymer is soluble. Polymers of molecular weights less than 10,000 which exhibit turbulence-suppressing effects in aqueous solutions are also useful. Polymers contemplated include polyacrylic acid, polyacrylamide, hydrolyzed polyacrylamide, sodium polystyrene sulfonate, polyvinylpyrrolidone, polyethylene oxide, dextran, dialdehyde starch, gu'ar gum, karaya gum, alginates, polyethyleneimine, carboxymethyl cellulose, variations thereof such as carboxymethyl hydroxyethyl cellulose, and many other water soluble polymers such as copolymers of acrylamide with other monomers forming water-soluble polymers. Illustrative copolymers are those obtained by the ethylenic polymerization of acrylamide with up to a major proportion e.g., 50 mole percent or so, of one or more, other Water-soluble comonomers such as acrylic acid, rnethacrylic acid, the alkali metal, amine and ammonium salts of acrylic and methacrylic acids, methacrylamide, fl-aminoethyl acrylate, B-aminoethyl methacrylate, N-methyl-[i-aminoethyl acrylate, N-methyl aminoethyl methacrylate, N,N-dimethyl B-aminoethyl methacrylate, diacetone acrylamide, and the water-soluble N-alkyl substituted acrylamide and methacrylamides such as N-isopropyl acrylamide. Still other comonomers of the watersoluble class are the alkali metal styrene sulfonates, and alkali metal vinylbenzoates, diallyl amines and disubstituted diallyl quaternary ammonium halides. Also useful a-re allyl alcohol, N-vinyl pyridine, N-vinyl pyrrolidone, and N-vinyl-2-oxaz0lidone. If desired, water-insoluble monomers can also be copolymerized with acrylamide to provide acrylamide polymers useful herein. To maintain the necessary water solubility, such copolymers will usually contain no more than about 25 mole percent of the water-insoluble comonomer. Illustrative of such comonomers are styrene, vinyl chloride, vinyli-dene chloride methylmethacrylate, and methacrylonitrile.

The ethylene oxide polymers which are effective are the long-chain polymers which are characterized by minimum of cross-linkages and high molecular weight.

Polyacrylamide, hydrolyzed polyacrylamide, and watersoluble copolymers of acrylamide such as are discussed above may be referred to as acrylamide polymers.

I prefer to use polyacrylamide which has been hydrolyzed to the extent of about 10% to about 40% conversion of its amide groups to carboxylic acid groups. Generally, commercial polyacrylamide is not hydrolyzed to an extent greater than about 40%, but as high as 65% has been reported.

Concentrations of polymer from about 10 p.p.m. to about 500 or more p.p.m. are useful, i.e., have at least some noticeable effect, but benefits approach the minimal at the lower end of this range and some slippage of the weft may be noted at the higher end with some polymers and some types of yarn. I prefer to use between about 50 p.p.m. and 400 p.p.m. More than 500 p.p.m. may be used when minimal slippage is noted due to the type of weft fed into the loom.

When dissolving the polymer in the water and pumping it into the jet, care should be taken to assure that as little air as possible in the form of bubbles is in the solution, since bubbles are compressible and cause interruptions in the jet stream. However, a certain number of interruptions of production per unit of time due to flaws, or the like, in the product are not unacceptable in the trade.

The polymer solution appears to maintain a superior grip on the weft at concentrations of polymer less than about 300 p.p.m. Monofilament wefts are apparently more diflicult to control in my process than yarns comprised of a number of staple fibers. But water including a watersoluble polymer will retain the weft better than plain water.

In addition to the above advantages, the high velocity and characteristically coherent stream achieved by my invention enable the operator to set and reset the jet stream with great accuracy.

Velocity of water jets in an Elitex model H125R water jet loom has been increased almost 50% by the use of 300 p.p.m. of 30% hydrolyzed polyacrylamide in the water, significantly increasing production in the loom.

I do not intend to be limited to the variations of my invention specifically discussed above. It may be otherwise practiced within the scope of the following claims.

I claim:

1. In a method of feeding a weft by a water jet, the improvement comprising adding to the water prior to its passage through the jet at least about 10 p.p.m. of a water soluble polymer having a turbulence-suppressing effect in aqueous solution.

2. Method of claim 1 in which the water-soluble polymer is an acrylamide polymer.

3. Method of feeding weft to a loom comprising passing water containing at least 10 p.p.m. of a water-soluble polymer, having a molecular weight of at least 10,000, through a nozzle under pressure to form a jet stream, feeding the weft into said jet stream, and directing the jet stream containing the weft through the Warp shed.

4. Method of claim 3 in which the water-soluble polymer is an acrylamide polymer.

5. Method of feeding a weft into a warp shed by means of a water jet, comprising passing both the weft and a solution of water-soluble polymer having a molecular weight of at least 10,000 simultaneously through a nozzle under pressure, and directing the jet stream formed thereby containing the weft through the warp shed.

6. Method of claim 5 in which the water-soluble polymer is an acrylamide polymer.

References Cited UNITED STATES PATENTS 2,998,029 8/1961 Zahradnik 139127 3,023,760 3/1962 Dever et a1 137-13 3,180,368 4/1965 Kobayashi 139-127 3,254,719 7/1966 Root 166-142 3,290,883 12/1966 Giles et al. 60-55 OTHER REFERENCES Union Carbide, T.I.B., Polyox Friction Reducing Agent for Aqueous Systems.

HENRY S. JAUDON, Primary Examiner US. Cl. X.R. 2267 

